An particle (charge ) of kinetic energy is fired head-on at an aluminium nucleus ( )

PHYSICS · Multi-part · Fermi University Physics · Electricity, Magnetism & Electromagnetism · Atomic, Molecular & Optical Physics · One-electron atoms and the origins of atomic structure

Reading the Spectrum, Ch The nuclear atom and the Bohr-Sommerfeld model

Problem

\alpha

particle (charge

2e

) of kinetic energy

5.0\,\mathrm{MeV}

is fired head-on at an aluminium nucleus (

Z = 13

). Treat the nucleus as fixed and use

e^2/4\pi\epsilon_0 = 1.440\,\mathrm{MeV\,fm}

. ((a)) Find the distance of closest approach

d

, in fm. ((b)) What kinetic energy would bring the

\alpha

particle to within

4.0\,\mathrm{fm}

of the centre of the nucleus, if Coulomb's law still held there? ((c)) Say why the answer to part (a) is an upper bound on the size of the aluminium nucleus and not a measurement of it.

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